Green spaces, excess weight and obesity in Spain

Int J Hyg Environ Health. 2020 Jan;223(1):45-55. doi: 10.1016/j.ijheh.2019.10.007. Epub 2019 Nov 1.

Abstract

Background: The epidemiological evidence on green spaces and obesity is inconsistent.

Objectives: To study the association of access to green spaces and surrounding greenness with obesity in Spain.

Methods: We enrolled 2354 individuals 20-85 years from urban areas of seven provinces of Spain between 2008-13. Subjects were randomly selected population controls of the MCC-Spain case-control study. We geocoded current residences and defined exposures in a buffer of 300 m around them: i) access to green space, identified using Urban Atlas, and ii) levels of surrounding greenness, measured by the Normalized Difference Vegetation Index. We examined excess weight/obesity as binary outcomes based on body mass index and waist-hip ratio. We examined effect modification by genetic factors, sex and individual socio-economic status and mediation by physical activity and concentrations of PM2.5 and NO2. To assess potential effect modification by genetic factors, we used a polygenic risk score based on obesity polymorphisms detected in genome-wide association studies. We used logistic mixed-effects models with a random effect for catchment area adjusted for potential confounders.

Results: Access to green space was associated with a reduced risk of excess weight/obesity after adjusting for confounders [excess weight: OR (95%CI) = 0.82 (0.63, 1.07), p-value = 0.143; abdominal obesity: OR (95%CI) = 0.68 (0.45, 1.01), p-value = 0.057]. In the stratified analysis, this association was only observed in women. Associations between surrounding greenness and excess weight/obesity were null or modest based on a 1 IQR increase in NDVI [excess weight: OR (95%CI) = 0.99 (0.88, 1.11), p-value = 0.875; abdominal obesity: OR (95%CI) = 0.91 (0.79, 1.05), p-value = 0.186]. The observed associations were not mediated by physical activity or air pollution.

Discussion: Access to green space may be associated with decreased risk of excess weight/obesity among women in Spain. Mechanisms explaining this association remain unclear.

Keywords: Body mass index; Green space; Obesity; Overweight; Surrounding greenness; Waist-to-hip ratio.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index
  • Case-Control Studies
  • Environment Design
  • Environmental Exposure
  • Environmental Health
  • Female
  • Genome-Wide Association Study
  • Humans
  • Male
  • Middle Aged
  • Obesity / epidemiology*
  • Residence Characteristics
  • Social Class
  • Socioeconomic Factors
  • Spain / epidemiology
  • Young Adult